Replicative exhaustion - how to induce senescence (Feb/15/2011 )

Hi,

I am interested in senescence induction of human fibroblasts to generate conditioned media. There seem to be a few ways to accomplish this (e.g. irradiation, replicative exhaustion, p16 lentivirus, exposure to H2O2, etc.) Does anyone have experience with any of these? Replicative exhaustion by repeatedly passaging cells seem to be the simplest method, but I'm not sure of the details, for example:

- duration/frequency of passaging
- how often I should change media
- whether or not we can store the conditioned media (if so how and for how long)
- any other things to keep in mind

Please feel free to throw in any other ideas that you think might be helpful. If you would like to recommend other methods that work better, please let me know as well.

Thanks!

CK

Anyone???